Forty patients with osteoarthrosis or rheumatoid arthritis were entered in a 4-week double-blind trial to compare the efficacy, safety and tolerance of a flurbiprofen 100 mg suppository formulation with indomethacin 100 mg suppositories. There were twenty patients each on indomethacin and flurbiprofen. Statistically significant improvements were reported for both treatments during the study with respect to morning stiffness, night pain and the overall progress of the patients. Both treatments were equally effective with respect to the amount of improvement shown for the parameters. No improvement was noted on either treatment with respect to grip-strength, functional capacity or the daily intake of analgesic therapy, while a marginally significant decrease in the erythrocyte sedimentation rate was noted on indomethacin. Both treatments were well tolerated with only a few transient and mild side-effects being reported. On the basis of this trial, flurbiprofen and indomethacin suppositories have equal therapeutic effects in the treatment of night pain and morning stiffness.